Auger type liquid freezing apparatus



Dec. 29, 1964 A. J. Ross AUGER TYPE LIQUID FREEZING APPARATUS 3Sheets-Sheet 1 Original Filed April 27, 1959 ff aY\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\9\\\\\ Dec. 29, 1964 A. J. RossAUGER TYPE: LIQUID FREEZING APPARATUS Original Filed April 27, 1959 3Sheets-Sheet 2 Dec. 29, 1964 A. J. Ross AUGER TYPE LIQUID FREEZINGAPPARATUS 3 Sheets-Sheet 3 Original Filed April 27, 1959 United StatesPatent O 2@ Claims. (Cl. 62-138) This invention relates to improvementsin apparatus for freezing liquids and is a division of my co-pendingapplication Serial No. 809,285, iiled April 27, I1959 and entitledLiquid Freezing Apparatus.

An important object `of this invention is to provide a liquid freezing`apparatus of the type employing a liquid storage cham'ber, an internalevaporator in the storage chamber and an `ice remover for removingfrozen liquid from the walls of the evaporator, characterized in thatthe apparatus can be readily assembled and disassembled to enablethorough cleaning of the several parts.

Another object of this invention is to provide a liquid freezingapparatus having a lfreezing, wall and an improved evaporatorconstruction for more uniformly cooling `the freezing wall over theentire operative surface thereof.

A further object of this invention is lto provide a liquid freezinapparatus in accordance with the foregoing object and in which therefrigerant accumulator is .located Iwithin the evaporator casing and soarranged as to maintain the liquilied refrigerant level along theevaporator Wall constant notwithstanding variations `in the liquefiedrefrigerant level inthe accumulator chamber.

Yet another object of this invention is to provide an intermittentlyoperated ifreezing `apparatus having a freezing fwall, a yrefrigeratingmechanism including a compressor for chilling the freezing wall, and amotor driven ice remover for removing frozen liquid trom the freezingwall, and characterized by the provision of an improved arrangement 4forfacilitating restarting of the freezing apparatus without causingabnormal loads on the ice remover motor `and compressor'.

Yet another object of this invention is to provide a liquid freezingappara-tus having an improved arrangement for constructing the condenserand mounting the refrigerant compressor `and the ice making head.thereon to provide a self-contained unit which is simple and compact inconstruction and which can be economically fabricated.

These, together with various ancillary objects and advantages of thisinvention will be more readily appreciated as the same becomes betterunderstood by reference to the following detailed description when takenin `connection with the laccompanying drawings wherein:

FIGURE l is a perspective view of the condenser coll construction withsome of the cooling and reinforcing rod-s removed for clarity ofillustration and with the compressor, ice making head 'and loat valveshown in phantom to illustrate the manner of mounting the same on thecondenser coil;

FlG. l2 is la fragmentary enlarged view on `the plane 2-2 of FIG. l,illustrating one corner of the condenser coil;

FIG. 3 -is a schematic view illustrating the controls for the liquid`freezing apparatus;

lFIG. 4 is a vertical sectional View illustrating one form of liquidfreezing head;

FIG 5 is a horizontal sectional vView Itaken on the plane `5 5 of FIG.4;

FIG. 6 is a fragmentary view taken on the plane 6 6 of FIG. 5;

lFIGS. 7 and 8 are fragmentary side elevational views illustrating thepin and slot construction for detachably interconnecting the parts;

ice

FIG. 9 is a vertical sectional view through a modified form of liquidfreezing head in which a refrigerant acciunulator is located within theevaporator;

rFlG. 10 is a horizontal sectional view taken on the plane i-dtt of FIG.9;

IFIG. ll is a vertical sectional view through a further modified Iformof liquid freezing head;

`FIG. l2 is a horizontal sectional View taken on the plane lf2-l2 ofFIG. l1; and

FIG. 13 is ya longitudinal sectional view through a liquid freezingapparatus `adapted to be mounted horizontally.

Reference is now made more specifically to FIG. 3 of the drawingswherein there is schematically illustrated :a refrigeration systemincluding a motor driven compressor lll having a refrigerant inlet liland an outlet l2. The compressed refrigerant is passed `from the `outletd2 through a tube 13 to a condenser coil 14 and then liquefiedrefrigerant `from the condenser coil is passed through `a refrigerantexpansion control, such as an expansion valve or the capilla-ry tube .15illustrated herein to lan evaporator 1.6. The refrigerant expands in theevaporator and the gaseous refrigerant is passed through a return line17 iback .to vthe inlet lll of the compressor lh. :The ice making head2l of the .present yinvention includes the evaporator d6, `a liquidjacket or casing 22 for storing a quantity of liquid in contact with thewalls of the evaporator, a liquid ow control va-lve 23 for controllingthe flow of liquid to the tank to maintain a preselected liquid leveltherein, `and a rotary ice remover 2S, herein sometimes referred to as ascraper, driven rby a motor 26 lfor removing the frozen liquid yfrom thewalls of the evaporator. The compressor motor is energized through acircuit includ-ing conductors 23 and 29 and switch apparatus is providedin the control circuit to control operation yot the compressor do, andhence control the freezing of liquid in the head 21. For reasons setforth hereinafter, 1a threewvay switch 31 is provided in the controlcircuit and is movable Ibetween a position engaging contact 31a toenergize the compressor motor, and a position engaging a `second contactSdb. The switch 3l may tbe operated in any desired manner, eithermanually or automatically. In the speciiic lform herein shown, theswitch 3l is automatically operated to a position closing contact 31awhenever the ice level in the storage `ibin 32 drops below `apreselected level. This may conveniently tbe achieved hy the provisionof a thermal loulb 33 at the `desired level in the storage hin, whichthermal bulb is connected through a capillary tube 34 to an expansibleoperator 35. When the ice moves out of contact with the bulb 33, theliquid -in the bulb expands and moves the switch @d upward-ly intoengagement with contact Sla.- When the ice again contacts the bulb 33,the liquid contracts and the switch 3l moves downwardly into engagementwith contact Sib. If desired, a main ofaon switch 37 may be connected inseries with the automatic switch 3d. The ice Iremover drive motor 26 isalso connected to the control circuit conductors 28 and 29,

through lines 38 and 39. A condenser cooling fan 4l may he provided ifdesired to control the condenser temperature and hence the outletpressure lof the compresser. As shown herein, the fan 4d is connected tothe control circuit conductors 28 and 29 through conductors i2 and 43and a pressure responsive switch 44 which is controlled by a pressureresponsive device 45 connected to the outlet side of the compressor lll.The outlet pressure of the compressor increases when the condense-rtemperature rises, to .thereby `automatically close 4the switch 44 and`start the fa-n 4l which cools the condenser rand reduces the outletpressure on the compressor.

Under certain adverse conditions, as when restarting the apparatus,liquid will freeze on the evaporator at a rate faster than the motordriven ice remover can remove the frozen liquid and cause stalling ofthe motor 26. Advantageously, a switch 46 may be provided in the mainpower circuit conductor 29 and controlled automatically, as by a device47, to open the circuit to the compressor lil and ice remover motor 26in the event of a freeze-up in the head 2l. As shown herein, thefreeze-up in the head is detected by a thermal bulb 4S which isconnected by a tube 49 to the expansible device 47. The bulb may bemounted in the liquid in the jacket or in heat conducting relation ftothe wall of the jacket to respond to 'the temperature therein andoperate the switch le to open the circuit when the liquid in the jacketfreezes up. Alternatively, a conventional thermal bulb or pressureswitch (not shown) may be located in the suction line i7 of therefrigerating apparatus to respond to the drop in temperature andpressure therein which occurs when the head 2l freezes up. When thecompressor is shut off, the head will warm up and the switch lo willthen automatically re-close and re-start the apparatus. The drive rnotor2K6 is advantageously either designed to withstand stalling currentwithout burning out, or is protected by a conventional thermal overloadswitch, to prevent damage in the event of such a freeze-up.

The condenser 14 may be advantageously formed in the manner shown inFIGS. 4l and 2 to support the several elements including the compressor,the freezing head and the liquid level control, and to form a partialenclosure therefor. 'With this arrangement, the condenser has a largeradiating surface and it is unnecessary in most installations to providea condenser cooling fan such as 4l. The condenser is formed from acontinuous tube bent to form a plurality of U-shaped sections Sil eachincluding a top portion Sla and side portions Sill) and Stic. TheU-shaped sections are disposed in spaced parallel relation and are eachinterconnected at their lower ends with one 4adjacent U-shaped sectionby an arcuate segment ddd which form support legs for the condenser. TheU-shape sections are secured together by means of generally horizontallydisposed wires or rods 5l which extend crossvvise of the side andtopportions of the inner and outer faces to brace the U-shape sectionsand to increase the heat radiating surface. The condenser cage may alsoinclude a rear wall which is connected to the rearrnost AU-shapcdsection Sil by an arcuate segment 54, and which rear wall includespreferably vertically extending straight sections 51.5 which areinterconnected by arcuate segments 55a in a serpentine coniiguration.Parallel reinforcing and heat radiating rods S6 are also secured as bybrazing or soldering to the inner and outer faces the parallel sectionsS5 to extend crosswise thereof. The cage also includes a bottom orsupport panel which is connected by a tubular segment Si; to the end ofthe tube sections forming the rear panel, and which bottom panelincludes straight sections all interconnected by arcuate segments olliin a serpentine configuration, with the straight segments extendingforwardly and rearwardly of the cage. The bottom also includesreinforcing and heat radiating rods 63 which extend crosswise of thesections el and preferably have the ends thereof extending outwardly torest on one of the rods 5l on the side portions of the lJ-shapedsections as best shown in FlG. 2, to support the bottom of the cage. Aplurality of wire ties 64 may be provided to additionally support andconnect the bottom and rear walls of the cage to the side and top walls.The motor driven compressor lll is disposed within the cage and has legs67 clamped to the bottom `avail as by a clamp plate 6d and fasteners 69.The freezer head 2l may also oe provided with an enlarged base plate 7lwhich is clamped to the bottom, as by a plate 72 and fasteners 73. Theliquid levelcontrol 23 may be mounted in any desired manner and asherein shown is mounted on the side of `the cage.

The liquid freezing head 2l is designed to enable ready disassembly ofthe evaporator lo, the scraper ZS and the casing or jacket 2l tofacilitate thorough cleaning of the i several parts. As shown in FlUS.4-12, the evaporator l' is made in the form of a cylindrical casing Sihaving a wall S2 at one end providing a closure for one end of thccasing. An enlarged head or base 83 is provided on the other end of theevaporator casing and includes an outwardly extending flange portion 83aand a depending slcirt portion b. The jacket 12 is in the form of asleeve which surrounds the head d3 to dene a liquid chamber 2intherebetween and is sealed thereto as by an O-ring 8d disposed in aperipheral groove in the head. The outer of the head is stepped toprovide a shoulder 96 which engages the lower end of the casing 22 tosupport the saine. The sleeve is detachably secured to the head as bypins carried by the head and which extend into slots Se in the sleeve.Advantageously, the slots 86 can be angularly spaced apart 9% from eachother so as to enable the sleeve its discharge opening lill to bepositioned in difiere-nt angular positions. The jacket 23 extends inspaced relation to the Walls of the evaporator Si to define a liquidchamber therebetween and the ice remover 25 is disposed in this chamberaround the evaporator Si. The ice remover is preferably in the form of aresilient axially expansible and contractibie helix having an inwardlyextending arm 8'? at one end which is attached to the drive shaft ftd ofa gear head motor 26. The motor is conv i irently detachably mounted onthe upper end of the jacket or casing Z2 to be supported thereby and, asshown herein, the motor is attached to a head @l which is removably'mounted on the upper end of the jacket. The head has an outwardlyextending dange 92 to which the motor is secured, and which flangeoverlies the upper end of the jacket Z2 to be supported thereon. Thehead is preterabrJ` formed with a concavity @la in the upper facethereof to collect any oil which may drip from the motor. Oil overflowAtubes 93 are provided on the head 9i to permit oil to drain from theconcavity Sula, which tubes are arranged to be received in slots 9dformed in the iacltet ZZ.

The motor shaft S8 extends through a bore Q5 in a central boss on thehead 9i, and a slinger 95 is attached to the shaft and ovcrlies the boretcprevent the draining of oil along the shaft and through the bore.Liquid is supplied to the liquid chamber through a preferably flexiblehose 9S which is connected to a nipple 99 on the water jacket Z2. Thecontrol valve 23 may be of any conventional construction which willmaintain the liquid level in the chamber at a level below the dischargeopening Lili in the liquid jacket 22. With this arrangement, the motor2d and head gli may be removed. to enable cleaning of the ice remover25, and the iacliet 22 detached from lower head S3 to facilitatecleaning of the interior walls of the jacket and the outer walls of theevaporator. While the axial pressure exerted by the screw 2.5 on theevaporator casing Si will be in a direction to draw the heads $3 and Mtoward each other, the slots and 9dhe jacl; t 2?, may advantageously beof the bayonet type shown in FlGS, 7 and S ito aid in preventingaccidental detachment of the heads from the water javnet. The connectionbetween the upper head 9i and the jacket L22 is preferably sutiicientlyloose to permit limited floating movement or the head and motor, asrequired to enable the icc remover 2' to align itself with theevaporator casing.

The refrigerant inlet and return lines l i7 respeceively extend throughthe lower head 33 into the chamber within the evaporator casing 3l, soas to not interfere with the removal of the jacket 22 or ice re mover 25from the evaporator. ln the embodiment shown in FlG. 4, the capillarytube l5 forming the inlet line extends in through a lateral opening wein the slrirt portion 83!) of the lower head, and then upwardly througha plug ltl, into the lower end of the chamber Sla in the evaporatorcasing Sl. The inner end 15o of the tube l5 is made J-shaped to directthe incoming refrigerant downwardly toward the bottom of the evaporatorcasing to agitato the refrigerant and lubricating oil and to preventblowing the incoming refrigerant upwardly to the refrigerant outlet. Thereturn conduit 17 also extends through the lateral opening 104 in theskirt portion of the head S3 upwardly through the plug 195 to a pointadjacent the upper end of the `chamber Sia. With this arrangement, thegaseous refrigerant will pass out through the return line 17, but noliquefied refrigerant will pass through the return line until the levelof the liquefied refrigerant reaches the upper end of the return line17.

As the liquefied refrigerant vaporizes, it absorbs heat and cools thewalls of the casing 81 to freeze liquid thereon. However, the coolingeffect is more pronounced in the portions of the evaporator casing whichare contacted by liquefied refrigerant. In order to obtain substantiallyuniform freezing along the Wall of the evaporator casing 81, it isnecessary to maintain the chamber 81a in the casing 81 filled withliquefied refrigerant. Accordingly, an accumulator should be provided toassure an adequate supply of refrigerant =in the system to maintain thechamber 81a filled with liquefied refrigerant.

The plug S is sealed to the walls of the evaporator casing 81 as bysoldering or brazing `and as shown herein is disposed in a counterbore106 in the casing. The plug is disposed at a level above the head S3,and above the lower end 2519 `of the ice remover 25, to prevent freezingof liquid on the walls of the evaporator casing below the lower end ofthe ice remover which would interfere with the free rotation of thesame. The portion of the casing 81 below the plug, and the hollow head83 are filled with a `suitable insulating material 10S.

In the embodiment of FIGS. 4-8, the arm $7 on the upper end of the iceremover is designed toaid in feeding the frozen liquid to the dischargeopening itil in the jacket 22. The arm is preferably threaded on thelower end of the shaft 8S in abutting relation to a shoulder 88a thereonso that the arm is firmly attached to the shaft to support the iceremover concentrically of the evaporator casing 81. The arm has asubstantial axial depth and closely underlies the upper head 91 and, asbest shown in FIG. 5, the leading edge 87a of the arm is inclined to aradial plane through the shaft, at least along the upper portion of thearm, to urge the fnozen liquid radially outwardly toward the dischargeopening MB1 as the arm rotates. Advantageously, the leading edge of thearm is also inclined downwardly and forwardly in the direction ofrotation of the arm, to also elevate the frozen liquid engaged by thearm, while forcing the same outwardly toward the discharge opening. Theice remover 25 extends into a notch in the underside of the arm and issecured thereto, as by welding. Preferably, the upper end of the helicalice remover 2S is spaced below the upper head 91 a distance less thanthe lead of the helix to compress the frozen liquid between the helixand the head before discharging the frozen liquid through the opening101.

'The liquid freezing head 21 illustrated in FIGS. 9 and l0 is generallythe same as that shown in FIGS. 4-8, and like numerals are utilized todesignate corresponding parts. The freezing head of FIG. 9 differsprimarily in the pro- Vision of a refrigerant accumulator within theevaporator casing S1 so as to eliminate the necessity of providing aseparate accumulator in the refrigeration system, and to also eliminatethe refrigeration losses attendant to such an external accumulator. Moreparticularly, a sleeve 111 is mounted on the plug 11%' to extendupwardly in the evaporator casing, in spaced relation thereto to definea cooling chamber 112 between the sleeve and the evaporator 81, and anaccumulator chamber 114 within the sleeve 111. The refrigerant inlentline extends upwardly through the plug 10:5 and discharges into thechamber 112 preferably adjacent its lower end. The refrigerant returnline 17 extends upwardly through the plug 165 and communicates with theaccumulator chamber 114i` adjacent its upper end. With this arrangement,the liquefied refrigerant enters through the line 15 and into thechamber 112, the excess liquefied refrigerant passing over the top ofthe isleeve 111 into the central accumulator chamber. As before, thegaseous refrigerant passes outwardly thnough the return line 17. Thus,liquefied refrigerant is maintained in contact with the entire innersurface of the evaporator casing 81, up to the upper end yof the innersleeve 111, notwithstanding variations in the level of the liquidrefrigerant within the central accumulator 111i.

FIGS. 9 and 1G also illustrate a slightly modified ice removerconstruction and arrangement for guiding the fnozen liquid to thedischarge opening.v As in the preceding embodiment, the arm 102 ispreferably threadedly attached to the shaft 8S in abutting engagementwith the shoulder 38a thereon. The arm is spaced below the head 21 and ablade 193 is positioned above the arm 192 to guide the ice toward thedischarge opening 101. The blade may conveniently be attached to theunderside of the head, as by a flange llfiSa on the blade.Advantageously, the blade may be formed of a resilient material such asrubber and extended downwardly to :a level below the upper edge of thearm. As the arm rotates past the blade, it defiects the blade from itsnormal position. As the blade returns to its normal position, it flicksthe frozen liquid through the discharge opening. In addition, theresilient blade minimizes the danger of injury if .la finger is insertedthrough the discharge opening 101. The blade extends from a pointadjacent the shaft r88 to the periphery of the jacket 22. The blade maybe positioned to intersect the discharge opening adjacent the trailingedge of the opening, to guide loose flakes to the opening, or it may bepositioned as shown in dotted lines in FIG. l0 to partially constrictthe opening. This tends to compress the flake ice and produce a moredense frozen product.

At times, the ice which is removed from the evaporator casing S1 doesnot rapidly move upwardly inthe jacket 22 and, instead, merely rotateswith the ice remover 25. In order to overcome this difficulty, ashoulder 10i) is formed on the inner periphery of the jacket 22 andextends closely adjacent the periphery of the screw. The shoulderextends crosswise of the convolutions of the ice remover 25 and ispreferably located adjacent the trailing edge of the discharge opening.Any ice which tends to rotate with the ice remover will engage theshoulder and, when the rotation of the ice is retarded, it will moveupwardly with the ice remover to the discharge opening.

In certain application such as in the larger size heads, or when the iceremover or the evaporator is formed of a material which will abraderapidly when the two are in rubbing contact, it is desirable to radiallysupport the free end of the ice remover 25 to prevent the same fromrubbing against the evaporator. As shown in FIG. 9, an annular bearing11i? is attached -to the lower end of the ice remover and slidab-ly androtatably surrounds the evaporator casing to radially support the iceremover, while permitting free axial expansion and contraction.

The liquid freezing head 21 illustrated in FIGS. ll and l2 is alsogenerally similar to that shown in FIGS. 4-8, and the same numeral-s areutilized to designate the corresponding parts. In the embodiment ofFIGS. ll and l2, a sleeve 121 is attached to the plug 105 and extendsupwardly in the cas-ing 81, to separate the latter into an outerfreezing chamber 122 and an inner accumulator chamber 123, whichfreezing and accumulator chambers are communicated with each otheradjacent their upper ends through an opening 124 in the upper end of thesleeve. An improved arrangement is provided for passing the liquefiedrefrigerant through the freezing chamber 122, to cause more uniformcooling of the Walls of the evaporator 81. For this purpose a helicalcoil 126 is disposed in the freezing chamber 122 and preferably issnugly received between the casing 81 and the sleeve 121. Therefrigerant inlet line 15 extends upwardly through Vthrough the chtite.

alcanzo the plug 105 and has a pontion 15b which extends through theaccumulator chamber and laterally through the sleeve 121. The end of thetube b has a ilared portion 15C which is connected to the upper end ofthe helical tube 12d to feed the liqueed refrigerant thereto. Theliqueed refrigerant flows downwardly in the helical tube and out throughthe lower end 126e thereof which communi cates with the freezing chamber122. rl`he liquefied refrigerant then flows upwardly in the freezingchamber between the convolutions of the tube to the upper end of thefreezing chamber from whence it passes through the opening 124 into thecentral accumulator chamber 123. As will be noted, the tube 12dfunctions as a bathe to cause the upwardly owing liqueiied refrigerantto pass in a helical path around the walls of the casing S1. Therefrigerant return lines 17, as in the preceding embodimen-ts,communicates with the accumulator chamber 123 above its lower end. As isapparent, the tube 12e and the outer chamber 122 will remain filled withliquefied refrigerant, notwithstanding variations in the liquid levelwithin the central accumulator chamber 123.

In order to compact and drain the fro-zen liquid which is delivered fromthe freezing heads, through the discharge openings 101 therein, anupwardly inclined discharge chute 131 may be provided. The chute 131(see FiG. ll) is attached to lthe casing around the discharge openingand is inclined upwardly therefrom so that the frozen liquid must beforced by the screw upwardly through the opening, to slightly compactthe frozen liquid passing In addition, any excess liquid in the frozenliquid or ice will drain back through the chute and into the chamber 21ain the packet 21.

In the embodiment of FIGS. ll and l2, a modied arrangement isillustrated for radially guiding a spiral ice remover 2S to limit radialshifting of the ice remover relative Vto the central evaporator casing.The casing 109 is of a suitable bearing material which will not abradeor cause abradng or" the ice remover when the ice remover rubsthereagainst. For example, the casing may be formed of nylon, and thecasing has an undulated inner periphery defining ribs lima which extendclosely adjacent the periphery of the ice remover to prevent the iceremover from shifting into rubbing contact with the evaporator. The ribsalso inhibit rotation of ice with the ice remover andV thereby aid inadvancing the ice to the discharge opening. In addition, the spacesbetween the ribs provide channels which permit liquid from the inlet 99to dow along the ice remover and into the spaces between adjacentconvolutions of the coil. The ends of the casingldl are counterbored asindicated at 10% and 165C to provide annular surfaces which surround theheads S3 and 91 in sealed relation thereto.

A furrther modified form of liquid freezing head Z1 is illustrated inFIG. 13, which head is particularly adapted for mounting in a horizontalposition. 16 is in the form of a tubular casing 151 having a wall 152 atone end thereof and a plug 153 connected to the other end of the casingin lsealed relation therewith. A tube 154 is attached to one end of thecasing and extends through an enlarged head 155. The tube isnon-sl-idably and non-rotatably secured to the head by means of a pin156 and an O-ring 157 is provided for sealing the interface between thetube and the head. A cylindrical jacket 161 surrounds the head and issealed thereto by an O-ring 162, the head being non-rotatably secured tothe jacket as by screws 163. As in the preceding embodiments, a

Ahelical ice remover 16d is disposed in the chamber 16151 within thejacket 161 and surrounds the evaporator casing 151. The helical iceremover has an inwardly extending arm 163 at one end, which arm issecured to a tubular drive shaft 164. The shaft is rotatably sup-portedin a head and seals 166 are provided in the hem for preventing leakageof liquid along the shaft. The head 165 is supported at the other end ofthe jacket 21 in sealed relation thereto as by O-rifng 1d?, and screwsldd The evaporator are provided for detachably ecuring the head inposition on the jacket, and to prevent rotary and axial shiftingmovement of the head. The jacket may be supported in any desired manner,as by pedestals 171, and the liquid to be frozen is introduced into .thechamber 161@ through an opening 112 adjacent the lower end of thechamber, the frozen liquid passing outwardly from the chamber through adelivery opening 173 adjacent the upper side of the chamber.

When mounting the freezer head in a horizontal position, it isadvantageous to support both ends of the evapo rator casing 151. Forlthis purpose a stub shaft 175 is secured to the end wall 152. of theevaporator casing and extends into tue hollow drive shaft 164 to beradially supported thereby. A thrust washer 17d is interposed betweenthe end wall 152, and the inwardly extending arm 163 on the screw 25 totake up the axial thrust on the shaft 16d during rotation of ythescraper.

The ice remover 16d is preferably in the form of a resilient axiallyexpansible and contractible coil which elongates and contracts as thefrozen liquid breaks away from the wall of the evaporator. 1n order tomaintain proper concentricity between the ice remover and theevaporator, provision is made for radially supporting the end of the iceremover remote from the shaft 164, while permitting axial movement ofthat end of the ice remover. This is achieved by the provision of acollar 151 which is rotatably supported on the tube 154 and is slidablyaxially therealong, and which collar is connected through a leaf spring1S?. to the end of the ice remover 16S, as by a fastener 183i. Thisradially supports the free end of the ice remover, while permittingaxial eX- pansion and contraction of the ice remover. While thearrangement for radially .supporting both ends of the evaporator casing,and also both ends of the ice remover is herein shown applied to ahorizontally mounted liquid freezing head, it is to be understood thatthis construction can also be advantageously employed in the larger sizevertically disposed freezing head. in order to prevent excessive lateralshifting of the ice remover relative to the central evaporator casing.

The refrigerant inlet and return conduits 15 and 17 extend through thetube 154 and through the plug 153 in scaled relation thereto. Theevaporator may advantageously be provided with a built-in accumulatorand for this purpose a sleeve 155 is disposed in the casing to e2;- tendbetween the plug 153 and the end wall 176 to separate the casing into anouter chamber 15in and an inner accumulator chamber 15th. The chambers15in and 151]) are communicated with each other adjacent one end, asthrough an opening 13d and a helical tube 137' is disposed in the outerchamber 151e. The iniet tube 15 extends through the chamber 151k andinto communication with one end of the helical tube 157. The liquefiedrefrigerant iiows from the tube 15 and through the helical tube 187. Theother end 187e of me tube discharges into the outer chamber 151e and theliqueed refrigerant then hows back through the space between theconvolutions of the tube 137 to the opening 18d and into the accumulatorchamber 151th. The refrigerant return line 17 has the end lci thereofcommunicating with the accumulator chamber adjacent the upper side toprevent drawing liquefied refrigerant back to the compressor. As isapparent, the shaft 1&4? may be driven in any desired manner and asherein shown there is provided a pulley 191 on the outer end of theshaft for connection to a suitable drive motor. While the lie-ad 21illustrated in FIG. 13 is designed to form a frozen product such aslieke ice and to discharge the same through the opening to a point ofuse or storage, the head is also adapted for cooling liquid in a tank.ln that event the jacket 16). could be omitted and the tube 15d andshaft 164 mounted in opposed walls of the tank to support the evaporatorand screw.

"fhen the ice in. ing apparatus is shut off after a period of operation7some difficulty is encountered when the apparatus is restarted. Thetorque required to drive the scraper and remove ice from the evaporatorrapidly builds up after restarting the ice making apparatus, to manytimes the torque required during normal operation, and then graduallydecreases to a normal operating torque. Consequently, in order toprevent stalling and damage to the drive motor, the drive motor 26 musthave a torque output many times that which is normally required. It hasbeen found that the provision of a heater for heating the refrigerant inthe evaporator effectively overcomes these difficulties. As shown inFlGS. 3, 4, 9, and ll, a tubular sheath 19S is mounted on the plug 1'35to extend into the chamber inside the evaporator casing Sli, and aheater i945 is disposed in the sheath. T he heater may advantageously beconnected through conductors i9? to 'the contact 31b of the three-wayswitch 3i, to be energized whenever the ice making apparatus is turnedoff. Similarly, in the embodiment shown in FIG. 13, a tubular sheath 198may be mounted on the plug E53 to extend into the accumulator chamberiSib and an immersion heater 199 disposed in the sheath for heating therefrigerant in the accumulator chamber.

It is considered that the overloading of the compressor and scraperdrive motor, upon restarting of the liquid freezing apparatus shortlyafter termination of a period of operation, occurs in the followingmanner. Since the condenser is very hot as compared to the evaporator,at the time the refrigeration apparatus is shut off, the refrigerant inthe condenser will be forced under the relatively higher pressure in thecondenser through the capillary tube and into the relatively coolevaporator. Within a short time after stopping the apparatus, most ofthe refrigerant in the system will have condensed in the evaporator; inthe suction line 17, and in the inlet of the compressor. When the liquidfreezing apparatus is thereafter restarted, the compressor will tend todraw liquefied refrigerant and thereby cause an abnormal load on thecompressor. Further, when the compressor does begin operation, theexcess liquefied refrigerant in the evaporator will vaporize rapidly andtemporarily cause the evaporator temperature to drop to a very low valueas compared to normal operating temperature. This causes the ice tobuild up on the evaporator at a higher than normal rate for a periodafter restarting the apparatus so that the torque required to operatethe ice remover also builds up a very high value, often of the order often times normal operating torque. After a short further period ofoperating the torque required to operate the ice remover again dropsback to a relatively low value. By providing the aforementioned heaterfor heating the evaporator, which is turned on immediately upon stoppingthe liquid freezing apparatus, the evaporator temperature is rapidlyraised to a temperature above the remainder of the system to preventexcessive condensing of refrigerant therein. In addition, the heaterhelps equalize the pressures in the system and facilitates restarting ofthe compressor. ln practice, the heater has been found to effectivelyeliminate the temporarily high torque load on the ice remover motor andthus permits the use of a relatively small motor aS compared to thoseotherwise required, without danger of stalling and damage to the iceremover motor.

I claim:

l. An apparatus for freezing liquids comprising, an evaporator casingclosed at one end, an enlarged head at the other end of the evaporatorcasing having a peripheral outer wall spaced radially outwardly fromsaid evaporator casing, a shell detachably mounted on said outer walland extending around the evaporator casing to form an outer chambertherebetween, refrigerant inlet and outlet passages extending throughsaid head and communicating with said evaporator casing for passingrefrigerant thereto to chill the walls of the evaporator casing, passagemeans communicating with said outer chamber for supplying liquidthereto, a second head detachably mounted on the other end of saidshell, drive means supported on said second head for removal therewith,and an ice removing device operatively connected to said drive means andextending into said outer chamber for removing frozen liquid from theevaporator casing.

2. An apparatus for freezing liquids comprising, an evaporator casingclosed at one end, an enlarged head at the other end of the evaporatorcasing having an outer wall spaced radially outwardly from saidevaporator casing, a shell detachaoly mounted on said outer wall andextending around the evaporator casing to form an outer chambertherebetween, refrigerant inlet and outlet passages extending throughsaid head and communicating with said evaporator casing for passingrefrigerant thereto to chill the walls of the evaporator casing, passagemeans communicating with said outer chamber for supplying liquidthereto, a second head detachably mounted on the other end of saidshell, and means including a helical ice remover rotatably mounted onsaid second head and extending into said outer chamber and surroundingsaid evaporator casing for removing frozen liquid therefrom.

3. An apparatus for freezing liquids comprising, an evaporator casingclosed at one end, a head member at the other end of the evaporatorcasing, said head member having an outer peripheral wall spaced radiallyoutwardly from the evaporator casing, an outer shell member surroundingsaid peripheral wall, one of said members having a groove formed in theregistering faces and an `S-ring in said groove for sealing theinterface between said shell and head members, said shell extending inspaced relation to said evaporator casing to form an outer charnbertherebetween, refrigerant inlet and return passages extending throughsaid head and communicating with said evaporator casing to passrefrigerant thereto for chilling the walls of the evaporator casing,passage means communicating with said outer chamber for supplying liquidthereto, and means including an ice removing device disposed in saidouter chamber and surrounding said evaporator casing for removing frozenliquid therefrom.

4. An apparatus for freezing liquids comprising a tubular evaporatorcasing closed at one end, an enlarged head at the other end of saidevaporator casing, an outer shell detachably mounted on said head andextending in spaced relation to the evaporator casing to define achamber therebetween, an ice removing device disposed in said chamberaround said casing, a second head detachably secured to said shell at apoint spaced axially from said one end of said casing, drive meansmounted on said second head for removal therewith and operativelyconnected to said ice removing device for rotating the same, a plugattached to said casing defining a seal thereacross at a point spacedaxially inwardly from said enlarged head to form an evaporator chamberin said casing, and refrigerant supply and return conduits extendingthrough said plug and communicating with said evaporator chamber.

5. An ice making apparatus comprising, an evaporator casing closed atone end, an enlarged head at the other end of said evaporator casingdefining an end wall extending outwardly from the evaporator casing anda peripheral wall extending around said end wall and spaced radiallyoutwardly from said evaporator casing, means for refrigerating saidevaporator casing including refrigerant inlet and return conduitsextending through the head into said casing, a sleeve having one endtelescopically fitting on said peripheral wall to enable ready axialremoval of the sleeve therefrom, a resilient seal ring interposedbetween said sleeve and said head to seal the interface therebetween, asecond head extending across the other end of said sleeve, drive meansmounted on said second head and having a drive shaft extendingtherethrough, an ice removing device connected to said drive shaft andextending into the chamber between said evaporator casing and saidsleeve, and quick disconnect means detachably and non-rotatablyconnecting said first head li l and said sleeve to enable easy removalof said sleeve for cleaning of the apparatus.

6. The combination of claim 5 wherein said quick disconnect meansincludes a pin and a slot formed on the interiitting parts of saidsleeve and said head.

7. An ice making apparatus comprising, an upright evaporator casingclosed at its upper end, an outer casing larger than said evaporatorcasing extending therearound to define a water chamber therebetween, ahead having a portion loosely extending into the upper end of said outereasing to center the head on the casing and a portion overlying theupper end of said outer casing to limit movement of the head into theouter casing, drive means mounted on said head for removal therewith andhaving a shaft extending downwardly therethrough, an annular iceremoving device connected to said shaft and extending downwardly intothe water chamber around the evaporator casing, and disconnect meansnon-rotatably attaching said head to said outer casing while enablinglimited iioating of the head relative to the outer casing to facilitatealignment of the ice removing device with the evaporator casing.

8. An apparatus for freezing liquids comprising, an evaporator casingclosed at one end, an enlarged head at the other end of the evaporatorcasing, an outer shell member having one end detachably mounted on saidhead, said shell member extending in spaced relation to said evaporatorcasing to form a chamber therebetween for receiving liquid to be frozen,refrigerant inlet and outlet passages extending through said head andcommunicating with said evaporator casing for passing refrigerantthereto to chill the walls of the evaporator casing, passage meanscommunicating with said outer chamber for supplying liquid thereto, asecond head detachably mounted on Y the other end of said shell, aself-contained motor and speed reducer unit mounted on said second headfor support thereby and for removal therewith and having a drive shaftextending through said second head, and an ice removing device deiininga generally annular cage open at one end to enable axial insertion andremoval of the ice removing device from around the evaporator casing andhaving means at the other end and overlying the closed end of theevaporator casing and connected to said drive shaft for rotationthereby.

9. ln an apparatus for freezing liquids, the combination of anevaporator casing closed at its upper end, an enlarged base at the lowerend of the evaporator casing, said base having an annular rim coaxialwith said evaporator casing and spaced radially outwardly therefrom anda shoulder extending outwardly from adiacent tie lower end of the rim, ashell detachably engaging said base and extending around the evaporatorcasing to form an outer chamber therebetween, said shell extendingaround said annular rim to be centered thereby and engaging saidshoulder to be axially supported thereby, refrigerant inlet and outletpassages extending through said base and communicating with saidevaporator casing to pass refrigerant thereto for ychilling the walls ofthe evaporator casing, passage means communicating with said outerchamber for supplying liquid thereto, an upper head extending across theupper end of said Shell, drive means mounted on said upper head, `and anice removing device de ming a generally annular cage open at one end toenable axial insertion and removal of the ice removing device fromaround the evaporator casing and having means at the other endoperatively connected to said drive means for rotation thereby.

l0. In an apparatus for freezing liquids, a tubular evaporator casing,means including an ice removing device or removing frozen liquid fromthe outer wall of the casing, means in said casing separating the latterinto an outer compartment along the walls of the casing and an innercompartment, inlet passage means communicating with said outercompartment, for feeding refrigerant thereto, means communicating theouter coml2 partment with the inner compartment at a preselected levelabove the lower end of the outer compartment to pass liquied refrigeranttherefrom only after the liquid th rein reaches said preselected level,and outlet passage means communicating with said inner compartment.

ll. in an apparatus for freezing liquids, a tubular evaporator casing,means including an ice removing device for removing frozen liquid fromthe outer wall of the casing, a sleeve in said casing and spacedtherefrom to delirio an annular outer compartment between the sleeve andcasing and an inner compartment within the sleeve, a first passage meanscommunicating with said outer cornpartment for feeding refrigerantthereto, means communieating said outer compartment with said innercompartment at a point ldisposed at a preselected level above the bottomof said outer compartment, and an outlet passage communicating with saidinner compartment above the bottom thereof for passing refrigerenttherefrom.

l2. The combination of claim ll including a bathe extending between saidsleeve and said casing for distributing the refrigerant around saidouter compartment.

i3. ln an apparatus `for freezing liquids, a tubular evaporator casing,means including an ice removing device for removing frozen liquid fromthe outer wall of the casing, a sleeve in said casing and spacedthereirom to define ar; annular outer compartment between the sleeve andcasing and an inner compartment within the sleeve, a iirst passage meanscommunicating with said outer compartment for feeding refrigerantthereto, means communicaring said outer compartment with said innercompartment at a point disposed at a preselected level above the bottomof said outer compartment, an outlet passage communicating with saidinner compartment above the bottorn thereof for passing refrigeranttherefrom, and a heater immersed in the refrigerant in said innercompartment operable to heat the refrigerant therein and to warm thewalls of said casing.

14. ln an apparatus for freezing liquids, a tubular evaporator casin g,means including an ice removing device for removing frozen liquid fromthe outer wall of the casing, a sleeve in said casing and spacedtherefrom to dene an annular outer compartment between the sleeve andcasing and an inner compartment within the sleeve, a helical tube insaid Outer compartment, a first passage means communicating with saidtube adjacent one end of the outer compartment for passing refrigerantthrough said tube to the other end of the outer compartment, said tubehaving an opening adjacent said other end of the outer compartment fordischarging the refrigerant into the outer compartment for flowtherethrough to said one end of the outer compartment, meanscommunicating said outer compartment with said inner compartmentadjacent said one end of the outer compartment, to pass refrigerant tosaid inner compartment, and outlet passage means communicating with saidinner compartment for passing refrigerant from the evaporator casing.

l5. The combination ot claim l4 wherein the convolutions of said tubespan the space between said sleeve and said casing to form a baille.

16. An apparatus for freezing liquids comprising a tubular evaporatorcasing closed at one end, an enlarged head at the other end of saidevaporator casing, an outer shell mounted on said head and extending inspaced relation to the evaporator casing to define a chambertherebetween, an ice removing device disposed in said chamber aroundsaid casing, a second head secured to said shell at a point spacedaxially from said one end of said casing, a plug attached to said casingat a point spaced axially from said enlarged head to form an evaporatorchamber in said casing, a sleeve attached to said plug and extendingupwardly in said evaporator chamber to separate the latter into an outercompartment between the sleeve and the casing and a central accumulatorcompartment, an inlet conduit extending through said plug andcommunicating with said outer compartment for supplying refrig- 13 erantthereto, said sleeve having an opening adjacent its upper end forpassing refrigerant from the outer compartment into the accumulatorcompartment, and an outlet conduit extending through said plug andcommunicating with said accumulator compartment above the bottomthereof.

17. In apparatus for freezing liquids, a l-iquid storage jacket, a drumshaped evaporator casing extending into said liquid storage jacket,means including an ice removing device for removing frozen liquid fromthe outer Wall of said evaporator casing, an inner accumulator casing insaid evaporator casing defining an accumulator compartment in said innercasing, means on one of said casings defining refrigerant flow passagesextending along and around the inside of said evaporator casing, arefrigerant supply passage means communicating with said ow passage forfeeding with said accumulator compartment and said refrigerant flowpassage at a point spaced therealong from said supply passage means forpassing refrigerant from the ow passage to the accumulator chamber, anda refrigerant'outlet passage means communicating with said accumulatorchamber at a point spaced above the bottom of the accumulator chamberfor passing refrigerant from the accumulator chamber.

18. The combination of claim 17 wherein said refrigerant flow passageextends in helical fashion along the inside of the drum shapedevaporator casing.

19. An apparatus for freezing liquids comprising, a chilling Wall, meansdefining a refrigerant chamber at one side of said chilling Wall, meansdefining a liquid storage chamber at the other side of said chillingwall, means including a motor driven compressor for passing refrigerantthrough said refrigerant chamber to freeze a layer of liquid on saidwall, motor driven ice removing means for removing liquid whichsolidiiies on said chilling wall, means responsive to the accumulationof an excessive layer of frozen liquid on said Wall for shutting off theapparatus, and means including a heater immersed in the refr-igerant insaid refrigerant chamber for heating the refrigerant therein when theapparatus is shut off.

20. A liquid freezing apparatus comprising a compressor, a condensercoil, a refrigerant expansion control and an evaporator connected in aclosed refrigeration loop, said condenser coil comprising a tube havinginterconnected U-shaped portions disposed parallel to each other anddefining top and side walls, said tube having parallel interconnectedportions defining a bottom wall, rods extending crosswise of saidparallel portions of said coil and connected thereto, said compressorbeing mounted on said condenser coil between said top and bottom Walls,a liquid freezing head mounted on said condenser coil and including achilling Wall having one side exposed to said evaporator to be cooledthereby, and motor driven scraper means for removing liquid whichsolidifies on said chilling Wall.

References Cited by the Examiner UNITED STATES PATENTS 2,145,331 l/39Arensberg 62-354 2,199,038 4/ 40 Brix-Hansen 62-354 X 2,299,414 l0/ 42Spiegl 62-3 54 X 2,585,020 2/52 Lessard et al.

ROBERT A. OLEARY, Primary Examiner.

19. AN APPARATUS FOR FREEZING LIQUIDS COMPRISING, A CHILLING WALL, MEANSDEFINING A REFRIGERANT CHAMBER AT ONE SIDE OF SAID CHILLING WALL, MEANSDEFINING A LIQUID STORAGE CHAMBER AT THE OTHER SIDE OF SAID CHILLINGWALL, MEANS INCLUDING A MOTOR DRIVEN COMPRESSOR FOR PASSING REFRIGERANTTHROUGH SAID REFRIGERANT CHAMBER TO FREEZE A LAYER OF LIQUID ON SAIDWALL, MOTOR DRIVEN ICE REMOVING MEANS FOR REMOVING LIQUID WHICHSOLIDIFIES ON SAID CHILLING WALL, MEANS RESPONSIVE TO THE ACCUMULATIONOF AN EXCESSIVE LAYER OF FROZEN LIQUID ON SAID WALL FOR SHUTTING OFF THEAPPARATUS, AND MEANS INCLUDING A HEATER IMMERSED IN THE REFRIGERANT INSAID REFRIGERANT CHAMBER FOR HEATING THE REFRIGERANT THEREIN WHEN THEAPPARATUS IS SHUT OFF.